1. Field of the Invention
Apparatuses consistent with the present invention relate to a rotational micro-electromechanical system (MEMS) device having a piezo-resistor sensor and, more particularly, to a rotational MEMS device having a piezo-resistor rotation sensor on a torsion spring of an axis of rotation.
2. Description of the Related Art
A micro optical scanner includes a driving comb electrode formed on a stage and a fixed comb electrode formed on a fixing unit for driving the stage. In a structure in which the driving comb electrode and the fixed comb electrode are vertically formed, a rotation angle of the stage may be measured based on the change of the overlapping region between the driving comb electrode and the fixed comb electrode.
However, the rotation angle measured using a capacity of the vertical comb structure is not accurate due to an etching tolerance of the comb electrodes. Therefore, there is a need to develop a sensor that can correctly measure a rotation angle of a stage.